Auger



PatehtedApr. 2, 1889.

..D- Mm BE Gm 0 P 0% i Q 5 V 0 a M. 0 M O 0 W N WW NITED STATES PATENTPrion.

FRANK C. GERARD, OF SEYMOUR, CONNECTICUT.

AUGER.

SPECIFICATION forming part of Letters Patent No. 400,659,

dated April 2, 1889.

Application filed \T 11116 18, 1888. Serial No. 277,414. (No model.)

, ble, easily sharpened, and of minimum first cost, and which, moreover,shall be so designed as to bore very rapidly, to bore a hole at anyangle without splitting the wood at starting, and to cut aperfectly-round hole upon the back of a board whether passed throughstraight or at any angle, the bit itself making a clean cut through, sothat splintering and punching out at the back of a board are whollyavoided. No bit, so far as I am aware, has heretofore been producedwhich combines these several desirable qualities in such a simple andpractical manner as my present construction, which was designed for theeX- press purpose of avoiding the various objections to different bitsnow in the market, and to produce in a satisfactory manner the sev: eralresults required from a tool of this class.

In the accompanying drawings, forming part of this specificatiomFigures1, 2,-and 3 are elevations of my novel bit, Fig. 1 showing thecutting-edge at the front and the cuttingspur at the back, Fig. 2showing the cuttingedge and the spur at the right and left,respectively, and Fig. 3' showing the spur at the front, thecutting-edge being at the back; and Fig. 4 is a bottom plan view.

In making my improved bit I preferably so form and twist the pod as toproduce two grooves of different widths, this for the reason that as Iemploy but one cutting-edge the chips must necessarily be carried out byone groove only. I therefore increase the size of this groove so as toavoid friction and insure free delivery of the chips.

1 denotes the shank; 2, the pod as a whole; 3, the delivery-groove, and4 the leading-screw.

This leading-screw is made single, of rapid pitch, and with the taperupon the lower side of the thread, the upper side being straight,

as shown in the drawings. This is in order to give a firmer and strongerhold in the wood.

5 denotes the cutting-edge, which in practice is a continuation of thethread of the leadingscrew. The upper surface back of the cutting-edgeleads directly into the delivery-groove. The under surface just back ofthe cutting-edge is made concave, as at 6, so as to make a thincutting-edge, which may be readily sharpened at any time by a few passesof a file, and which will permit the wearing away of considerable of themetal without impairing the efficiency of the bit in the slightest. 7denotes the cutting-spur, which is placed opposite to the cuttingedge.This cutting-spur is supported and strengthened by a floor, 8, formed bythe solid metal of the pod at the beginning of the upper side of thedelivery-groove, as viewed in Figs. 2 and 4.

It will be noticed (see Fig. 2) that the cutting-edge lies at aconsiderably lower horizontal plane than the .floor 8, which supportsthe spur, and, furthermore, (see Fig. 4,) that the front of floor 8 iscut away, as at 9, so that the entire front of the spur may besharpened, making it cut clear to its base, as indicated in Figs. 3 andt. This spur is made to flare outward slightly in the usual manner, andextends downward below the cutting-edge, as shown in Fig. 2, so that inboring a perfectly-round chip is cut out by the spur in advance of thecutting edge. By cutting away the front of floor 8, as at 9, andsharpening the front of the spur clear to its base, I insure that inboring through a board a perfectly-round hole shall be made at the backand avoid all danger of the bit punching through and splintering thewood, no matter at what angle the hole may be bored, and by removingmetal at the lower end of the pod opposite to the cuttingedgei.'e.,raising the plane of floor 8, I avoid all friction, as the cutting-edgeremoves chips in forcing its way into the wood.

In use the laying out of the hole is all performed by the single spurupon one side of the bit, the cutting away of the wood is all performedby the single cutting-edge at the opposite side of the bit, and theentire removal of the chips takes place through a single delivery-grooveleading back from the cutting-edge. The exact height of the plane offloor 8 at the base of the spur relatively to the cutting-edge is notessential, so long as sufficient metal is cut away to avoid any frictionupon the wood, leaving the cutting-edge free to cut away the wood asfast as it is drawn in by the leading-screw.

Having thus described my invention, 1 elaim- 1. An anger or bit havingupon one side of the leading-screw a cutting edge concaved upon itslower side, and upon the other side a cutting-spur sharpened to its baseand supported by a floor, 8, cut away at the front, said spur projectingbelow the plane of the cuttingedge, and the plane of the latter beingbelow the plane of floor 8, substantially as and for the purpose setforth.

2. An anger or bit having upon one side of the leading-screw acutting-edge, and upon the other side thereof a cutting-spur supportedby a floor, 8, cut away at the front, the entire front of said spur beinsharpened so that it will out to the base, as and for the purpose setforth.

An anger or bit having a leading-screw the threads of which are straightupon the upper side and inclined upon the lower side, a cutting-edgeforming a continuation of the thread of the screw, and a euttin g spurupon the opposite side, the horizontal plane at the base of the spurbeing higher than the cutting-edge, as and for the purpose set forth.

4. A double-groove anger or bit having a pod twisted to form adeliverygroove wider than the other groove, a single cutting-edge at thebase of the delivery-groove, and a single cutting-spin opposite to thecutting-edge, the plane at the base of the spur being higher than theplane of the cutting-edge, as and for the purpose set forth.

In testimony whereof I affix my signature in presence of two witnesses.

FRANK C. GERARD.

Vitnesses:

E, J. KIMPTON, EDWARD E. HoLnnooK.

